single threaded works better

internal_filesystem/apps/com.example.camtest/assets/camtest.py

@@ -75,6 +75,8 @@ def close_button_click(e):
     global keepgoing
     print("Close button clicked")
     keepgoing = False
+    th.remove_event_cb(try_capture)
+    show_launcher()
 
 
 def snap_button_click(e):
@@ -124,6 +126,7 @@ def qr_button_click(e):
         stop_qr_decoding()
 
 def try_capture(event, data):
+    print("capturing camera frame")
     global current_cam_buffer, image_dsc, image, use_webcam, keepgoing
     if not keepgoing:
         print("try_capture called while keepgoing==False, aborting...")
@@ -262,19 +265,33 @@ if cam and keepgoing:
     th.add_event_cb(try_capture, task_handler.TASK_HANDLER_STARTED)
 
 
-while appscreen == lv.screen_active() and keepgoing:
-    time.sleep_ms(100)
+#while appscreen == lv.screen_active() and keepgoing:
+#    print("camera running")
+#    time.sleep_ms(100)
+#    lv.tick_inc(100)
+#    lv.task_handler()
 
-print("camtest.py: stopping...")
-if cam:
-    th.remove_event_cb(try_capture)
+def check_running(timer):
+    if lv.screen_active() == appscreen:
+        print("camtest.py is still foreground")
+    else:
+        print("camtest.py lost foreground, cleaning up...")
+        timer1.delete()
+        if cam:
+            th.remove_event_cb(try_capture)
+        
+        if use_webcam:
+            webcam.deinit(cam)
+        elif cam:
+            cam.deinit()
+        print("camtest.py cleanup done.")
 
-if use_webcam:
-    webcam.deinit(cam)
-elif cam:
-    cam.deinit()
+timer1 = lv.timer_create(check_running, 1000, None)
 
-print("camtest.py: showing launcher...")
-show_launcher()
+
+#print("camtest.py: stopping...")
+
+#print("camtest.py: showing launcher...")
+#show_launcher()
 
 

internal_filesystem/apps/com.example.helloworld/assets/hello.py

@@ -16,8 +16,18 @@ lv.screen_load(scr)
 
 # END OF COPY-PASTE FROM https://sim.lvgl.io/v9.0/micropython/ports/webassembly/
 
+
+def check_running(timer):
+    if lv.screen_active() == scr:
+        print("hello.py is still foreground")
+    else:
+        print("hello.py lost foreground, cleaning up...")
+        timer1.delete()
+
+timer1 = lv.timer_create(check_running, 1000, None)
+
 # Added: wait until the user navigates away instead of stopping immediately.
-while lv.screen_active() == scr:
-    import time
-    time.sleep_ms(100)
-print("User navigated away from the HelloWorld app. Bye bye!")
+#while lv.screen_active() == scr:
+#    import time
+#    time.sleep_ms(100)
+#print("User navigated away from the HelloWorld app. Bye bye!")

internal_filesystem/lib/mpos/apps.py

@@ -92,7 +92,8 @@ def start_app(app_dir, is_launcher=False):
     manifest_path = f"{app_dir}/META-INF/MANIFEST.JSON"
     app = parse_manifest(manifest_path)
     start_script_fullpath = f"{app_dir}/{app.entrypoint}"
-    execute_script_new_thread(start_script_fullpath, True, is_launcher, True)
+    #execute_script_new_thread(start_script_fullpath, True, is_launcher, True)
+    execute_script(start_script_fullpath, True, is_launcher, True)
     # Launchers have the bar, other apps don't have it
     if is_launcher:
         mpos.ui.open_bar()